Method for removing oil from the shell of the cashew nut



E. RJ HUGHES Dec. 9, 1930.

MElHOD FOR REMOVINGOIL FROM THE SHELL OF THE CASI-IEW NUT .Filed Nov. 29", 1926 A ARAmNG MAcHlME SUOTION PUMP Am 'nem DISCHARGE D00 OUTERENVELOPE" 3 0R WIND CELLULAR STRUCTURE Z WITH OILHELDTHEREIN T0 SUCTI 0NI Header for Jz/ /eafea INVENT R www, A

Hls A1 RNEY Patented Dec. 9, 1930 UNITED STATES PATENT" OFFICE EDWARD R. HUGHES, F MORRISTOWN, NEW JERSEY, ASSIGNOR T0 THE HARVEL COR- PORATION, A CORPORATION OF NEW JERSEY METHOD FOR REMOVING' OIL FROM THE SHELL OF THE CASHEW NUT Application led November 29, 1926. Serial No. 151,510.

The present invention relates to method and -apparatus for removing the oil from the cellular shell of the cashew nut.

Various objectsI and advantages of the invention will be obvious from the following particular description of forms of apparatus and of methods and steps embodying the invention or from an inspection of the accompanying drawing; and the invention also con# sists 'in certainv new and useful features of construction and combinations of parts and in certain processes, methods and steps hereinafter set forth and claimed.

In 'the accompanying drawing there is shown for purposes of illustration forms of apparatus embodying the invention and also an illustration of the structure of the cashew nut. in which: y

Fig. 1 is a longitudinal view in part sec- .20 tion of a cashew nut.

Fig. 2 is a diagrammatic illustration in elevation of one form of apparatus, and

Fig. 3 is a diagram in elevation and section of another form of apparatus embodying the invention.

In Fig. 1 of the drawing is illustrated a cashew nut having a kernel or meat portion 1 about which occurs a thin paper like casing similar to the inside skin nexty to the kernel of the peanut. About the kernel, over said inside skin, is an inner hard shell Which -is about 15 of an inch in thickness. Spaced from the inner skin by a cell`ular structure 2 is a hard outer shell or rind 3. This cellular space extends inthe neighborhood of threesixteenths or a quarter of an inch from the inner hard shell to the outer shell, the cell walls run radially between the inner hard shell and the outer shell 3 and are more or less discontinuous, and the outer shell is about one-thirty-second of an inch in thickness. The space or cells between the inner hard shell and the outer shell is occupied by a'liquid or oil which comprises cardol and anacardic acid and which is useful in the arts generally. The kernel is also useful, it being edible and valuable for the oil thereof which is different from the shell oil and has various uses. The kernel oil is' a true'oil somewhat similar to -peanutoil or cottonseed oil,

the shell oil is not of the same nature but folr convenience is herein kwtermed the shell o1 In Fig. 2 of the drawing is diagrammati-` cally shown an abrading machine 6 such as a tumbling mill with angular pebbles or metal lumps in it for abrading the outer shell of the cashew nut. A tube or chute 8 connects the mill 6 with an oven 10l and two valves or stops l2 and 14 serve to shut oft' either or both thesmill 6 and oven 10 from a space in said tube 8. A suction pump 16 connects with the top of the oven 10 with a valve 18 between them, andan air tight door 20 covers a discharge opening at the bottom of the oven'. A gas heater 22 with a supply pipe 24 and valve 25 therein serve for heating said oven 10.

In the use and operation of this embodiment of the invention cashew nuts in their shell are` loaded into the mill 6 and are tumbled therein to abrade the outer shell thereof. After a charge has been tumbled and abraded they are discharged into tube 8 with the valve 14 closed. In the meantime oven 10 has been heated to about 400 to 7 50 F. byburner 22 and evacuated by pump 16. After a charge has been unloaded against said valve 14 said valve 12 is closed and valve 14 opened to discharge the nuts into the oven 10. The change in temperature of the nuts raises the pressure therein whereby is caused the discharge of the shell oil from the cells defined by the radial walls and outer shell 3 into the oven. The oil and the nuts are then discharged from the oven by door 20. The temperature of the oven when evacuated by pump 16 before putting a charge of nuts thereinto is preferably made below the carbonizing point ofthe shell oil 7 for example, at 600 'F.but various tem- 15. when a vacuum. to about one-tenthofan ator without the abrading the-suction pump is not used in some cases because the pressure produced in the shell is sufficiently greater than atmospheric to break the shell and expel the oil.

When the nuts are abraded the shell 3 is preferably cut through to provide an opening outwardly from the cells defined by said, shell 3 and the radial walls between it and the kernel 1. The degree of vacuum, when vacuum is used, can be made to depend o n the temperature used because the higher the' temperature the higher the pressure within -the shells. When no vacuum at `al1 is used the.

temperature can be about 600O to 650 F., and

mosphere is used then the temperature can be about 400o to 500 F.f These are merely as examples since other values .of temperature and pressure can be used. The shells are abraded to cut through" into the cells or topartly cut through and weaken the outershell and when so partly or completely cut through the wall. 40

through-a temperature of about 500 F.. is used at about one-tenth of an atmosphere pressure. The internal pressure produced in the liquid in the shell will clear .the liquid out of the shell in about tive seconds or even less. After the larger portion of the vliquid has been' forced out the residue can be drained out by leaving the shells to stand Aeither at normal temperatures and pressures or at raised temperature and/or at reduced pressure.

'At the temperatures cited the pressure produced in the liquid in the cells within. the shell is great enoughto burst open the shell if unabraded or abraded to partly cut In the preferred form, for rapid discharge of the shell oil from the shell, the shell is. braded at a number of points. l

At higher temperatures say 500o to 900 F. the suction pump 16 is left off and said door 20 left open'and thenuts and oil raked outl therethrough as rapidly as they come into said oven 10 because at these temperatures and normal pressure the sudden entrance of the nutsinto the high temperature zone will raise a sudden pressure in the nuts which will burst the shell 3 and force the liquid out At the highest temperature carbonization of the shell-liquid is kept nil or at a minimum by taking it out of the oven as quickly as it comes' in because it will take an appreciable interval of time for the liquid to get up to the carbonizing temperature which is not below 750 to 800 F. By this arrangement 'the gocess can be made substantially continuous cause the valves 12 and 14 can both be left open and a continuous stream of abraded or unabraded nuts passed through said slanting chute 8 where the temperature will be effective to force .the liquid out of the shells 3 vacuum is used to aid in lproducing a pressure diferential. between the outside and'inside of the nut shells at the lower temperature, for example at about 40.0 F.

At the lower temperatures no appreciable quantity of the oil of the kernel is driven olf and at the higher temperatures if any of the kernel oil is present it willl be vaporized 0H.

vIn Fig. 3 of the drawing is -diagrammatically shown an endless conveyor belt having cleats 32 thereon which passes in the direction of the arrow around the spindles 34, 34 and under the spindles 36, 36 to go down in to thefvat or tank 38, up into the inverted box and horizontally for a distance therein, then downunder the edge of said box and thence up out of and down, under and back around said tank 38.- A chute 42 .serves to feed abraded or unabraded nuts to said conveyor 30 and a pipe 44 connects through a` is Cashew shell oil forms a liquid seal for the' interior of said inverted box/l0. Y The sup` porting-rollers as well as the rollers 34,

34 within box 40'can be heated by gas or steam to supply heat to nuts intheirpassage through said box.V The apparatusv of this ligure can be operated `in manners similar tothat described for Fig. 2, but this has .the additional feature of being adapted for an automatically continuous process; the ex pelled oil flows from the nuts into tank 38 and.

out4 through said notch 46.

`Although there is shown anddescribed and is pointed out in the annexed claims certain novel features of the invention, it will 4be understood that v arious. omissions, substitutions and changes in the several steps of'- the processes and in their operation and in the 'form and details of the apparatus illi1strated may be made byv those skilled in the invention.

Having thus described 'invention what I I claim and desire to secure by Letters Patent is 1. The method of removing the liquid from the cellular structure within 'the shell of the Cashew nut which consists in subjecting the nuts to a sudden change from about normal 'temperature to about the charring tempera- 65 ,particularly at'the lower end thereof from. 2. The method of removing'the liquid from I art without departing from the spirit yof the 40 change in temperature to 'a point below` the the cellular structurewithin the shell of the cashew nut which consists in subjecting the nuts to a sudden upward change in temperature to produce an explosive pressure within said cellular structure, and at the same time subjecting the nuts t0 a sudden downward change in pressure, whereby said liquid is forced out from the shell.

3. The method of removing the liquid from the cellular structure within the shell of the Cashew nut which consists in weakening the shell and subjecting thenuts to a sudden upward Vchange of temperature to produce an explosive pressure within said cellular structure whereby said liquid is forced out from the shell.

4. The meth'od of removing the liquid from the cellular structure within the shell of the Cashew nut which consists in weakening the' shell and subjecting the nuts to a sudden upward .change in temperature to produce an explosive pressure within said cellular structure, and at the same time subjecting the nuts to a sudden downward change in pressure, vlhela'eby said liquid is forced out from the s e 5. The method of removing the liquid. from the cellular structure of the shell of the cashew nut which comprises moving the nut through a heated zone to produce a pressure in said cellular structure of the nut whereby the liquid therein is `forced out from the shell, the temperature of the high temperaturezone and the rate of movement of the nut through the high temperature zone being relatively7 adjusted to avoid charring of the shell liquid.

6. The method of removing the liquid from the cellular structure of the shell of the Cashew nut which comprises subjecting the nut to a comparatively sudden upward charring temperature of said liquid, to produce a pressure in said cellular structure whereby the liquid therein is forced out from the shell.

7. The method of removing the liquid from i the cellular structure of the shell of the cashew nut which comprises weakening of the outer shell ofthe nut and subjecting the nut to increased temperature to produce a pressure in the cellular spaces of the shell sufficientto force the liquid from the shell.

Signed at Hoboken in the county of Hudson and State of New Jersey, this 24th day 'of June, A. D. 1926.

EDWARD R. HUGHES. 

